1. Field of the Invention
The invention is concerned with electrodeposition of polymers in aqueous dispersion onto conductive surfaces to form cross-linked coatings wherein the article which comprises such surfaces is the cathode in an electric current carrying loop.
2. Description of the Prior Art
U.S. Pat. No. 3,697,398 describes a process for electrodepositing water soluble sulfonium polymers. However, in that patent there is no disclosure of the electrodeposition of polymers of sufficiently high molecular weight and low charge desnity to be water insoluble. The electrodeposition of other polymers in a water soluble form, i.e., water soluble, cationic epoxy resins, is described in U.S. Pat. No. 3,793,278. Cathodic electrodeposition of aqueous dispersions of material stabilized by amine and ammonium type surfactants is described in U.S. Pat. No. 3,159,558.
Another application of the present applicants, Ser. No. 430,105 filed Jan. 2, 1974, now U.S. Pat. No. 3,873,488, describes aqueous dispersions of water insoluble polymers stabilized with sulfonium cations which are suitable for cathodic electrodeposition. There is no suggestion in that application of structured-particle latexes.
One of the problems of the art is that in order to form smooth coatings it is necessary that a coating material must be sufficiently soft to permit some flow yet the coated material must have appropriate properties for the intended use. Accordingly, it would be desirable to have compositions and methods by which coatings could be readily cross-linked at appropriate times to provide articles having coatings of desired properties. It would be especially desirable if such a process were available which did not require the addition of curing agents and/or further process steps.